With age a large portion of the population develops arterial obstructions formed by fats, fibrous material and calcified deposits, resulting in a diminished blood circulation. The disturbance to blood flow that these obstructions cause can induce blood clots which further diminish or block the blood flow. When this process occurs in the arteries serving the heart muscles it is referred to as a heart attack. Presently such obstructions are circumvented surgically by grafting a bypass or they are treated by angioplasty with a catheter equipped with a balloon which is inserted, over a guide wire, into the obstruction through the arterial system and then inflated to expand the obstruction's lumen. Problems with this treatment are that it injures the arterial wall and may burst it and in certain cases it is ineffective. Further, it creates a rough lumen and does not remove the obstruction material out of the arterial system, therefore in a case of a heart attack, immediate angioplasty carries the risk of dislodging the blood clot and allowing it to move down stream creating further damage.
The objective of the present invention is to provide a catheter rotatable over a flexible guide-wire, equipped with a tubular-blade attached to its front end, that would cut and extract the obstruction material, including blood clots if present, create a smooth lumen and would not crack or injure the arterial wall. The mechanical atherectomy system should be produceable in diameters down to around 1 mm (millimeter) and a length of up to a meter to be able to reach and enter small and remote arteries. Preferably, the operation of the mechanical atherectomy system would resemble the operation of present catheters, as much as possible, so present skills of the medical staff can be utilized. This and other objectives of the invention will become apparent from the following discussion and the accompanying drawings.